“Mice that drank pomegranate juice were able to significantly reduce the progression of atherosclerosis, [by] at least 30 percent,” said study co-author Dr. Claudio Napoli, a professor of medicine and clinical pathology at the University of Naples School of Medicine in Italy.

The findings appear in this week’s issue of the Proceedings of the National Academy of Sciences.

Pomegranates, a native Middle Eastern fruit, are finding their way into more and more homes in the United States. The fruit contains crunchy seeds surrounded by juicy pulp and is a good source of potassium, vitamin C and antioxidants, according to the U.S. Department of Agriculture (USDA).

“Pomegranates are fun to eat, but messy,” noted Samantha Heller, a senior clinical nutritionist at New York University Medical Center. For that reason, she said, “juice may be a better option.”

Napoli and his colleagues tested the effects of pomegranate juice in mice that were bred to have high cholesterol and on human heart cells in culture.

Previous studies, according to Napoli, have suggested the antioxidants found in pomegranate juice might reduce plaque buildup on artery walls and reduce oxidative stress on endothelial cells, the cells that line blood vessels. These cells produce nitric oxide, a substance that helps the blood vessels relax.

The researchers found that heart cells treated with pomegranate juice had a 50 percent increase in nitric oxide production, and that mice given pomegranate juice reduced the rate of plaque buildup by about 30 percent.

The researchers don’t know the exact reason why pomegranate juice appears to protect artery walls from fatty deposits, but they suspect that the increased nitric oxide production may play a role, and that polyphenols — powerful antioxidants contained in pomegranates and other foods — may directly protect the arteries by reducing oxidative stress.

Other fruits and juices that contain polyphenols include blueberries, cranberries, oranges and grapes. Red wine also contains polyphenols, Napoli said.

Heller pointed out that while pomegranates are very healthy and high in antioxidants, they can be expensive and aren’t always easy to find. Plus, she said, “all fruits and vegetables are just packed with healthy phytochemicals.” Examples she cited as being high in antioxidants include berries, beans, apples, pecans and artichokes, just to name a few.

Heller also noted that the study was done primarily on mice and that data from mice don’t always extrapolate to humans. But, she added, “the phytochemicals in pomegranates, which are also present in other fruits and vegetables, are really very good for us, and do help prevent certain chronic diseases like heart disease and cancer.”

Napoli said that while it is hard to extrapolate data from mice to humans, an equivalent amount of pomegranate juice for humans would be the equivalent of about 16 ounces daily.